From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0; YComp 5.0.0.0; H010818) Description of problem: Attempting to add a disk to an active array fails. Version-Release number of selected component (if applicable): mdadm-1.4.0-1 How reproducible: Always Steps to Reproduce: 1.mdadm -Cv /dev/md2 -l0 -n9 -c128 /dev/sd{a,b,c,d,e,f,g,h,i}1 2.mke2fs -b 4096 -j /dev/md2 3.mount /dev/md2 /mnt 4.mdadm /dev/md2 --add /dev/sdj1 Actual Results: mdadm: hot add failed for /dev/sdj1: Invalid argument Expected Results: Device should be added to active array /dev/md2. Additional info:
From Doug Ledford. No, this will never work. They are creating a raid0 array. Raid0arrays have no redundancy and don't support spare drives. If you have araid5 array and add a disk, it doesn't make the array larger, it justputs a spare disk in the array so that reconstruction can startautomatically in the event one of the regular disks fails. If you want to add a disk to an array and have it actually increase the size of thearray, then you have to use the raidresize (or something like that,can't remember for sure off the top of my head, but it's on the rescueCD) to recreate the array with the new disk and the utility takes careof shuffling all the data into the right positions on the disks so thatit ends up just being a larger array with your data still intact (then you have to use resize2fs to increase the filesystem size as well).